Influence of Partial Wetting on Single Catalyst Pellet Selectivity in Gas-Liquid Multireaction Systems

一些具有重要商业价值的化学品是在滴流床反应器中生产的，在那里，气体和液体反应物同时流经固定的催化剂床。这种三相体系的一个重要特征是，催化剂颗粒可能暴露在极不均匀的环境中，因为流动的液体可能只部分接触(湿)颗粒表面。部分润湿可以提高或减缓反应的速度，这取决于反应是气体反应物限制还是液体反应物限制。这项拟议工作的目的是设计一种机制，使反应器设计者能够预测与部分润湿相关的多相传输如何改变固有的催化选择性。PI计划为该系统进行实验和建模工作。首先，将建造一个单一的颗粒反应器，并测量反应速率。然后，将四个球形颗粒组合在一起，模拟大型燃料反应堆中的填充条件。在这个装置中，可以创建液袋，并评估它们对反应速率的影响。因此，将有设施直接测量总反应速率(选择性)和润湿效率之间的关系。

Some commercially important chemicals are produced in trickle bed reactors where gaseous and liquid reactants flow cocurrently down through a fixed catalyst bed. An important feature of such three-phase system is that the catalyst pellet may exposed to an extremely nonuniform environment because the flowing liquid may only partially contact (wet) the pellet surface. Partial wetting can enhance or retard the rate of a reaction depending on whether the reaction is gas reactant limiting or liquid reactant limiting. The purpose of the proposed work is to devise a meachanism which will enable reactor designers to predict how the intrinsic catalytic selectivity is altered by the multiphase transport associated with partial wetting. The PIs plan to do both experimental as well as modelling work for this system. Initially, a single pellet reactor is to be constructed and reaction rates will be measured. Then four spherical pellets will be put together to simulate packing conditions in a large fuel scale reactor. In this setup liquid pockets can be created and their effect on the reaction rate evaluated. Facilities will thus exist to measure directly the relationship between the overall reaction rates (selectivity) and the wetting efficiency.